selftests/bpf: add CO-RE relocs modifiers/typedef tests

Add tests validating correct handling of various combinations of
typedefs and const/volatile/restrict modifiers.

Signed-off-by: Andrii Nakryiko <[e-mail]>
Acked-by: Song Liu <[e-mail]>
Signed-off-by: Alexei Starovoitov <[e-mail]>

tools/testing/selftests/bpf/prog_tests/core_reloc.c

···
 	.fails = true,							\
 }
 
+#define MODS_CASE(name) {						\
+	.case_name = #name,						\
+	.bpf_obj_file = "test_core_reloc_mods.o",			\
+	.btf_src_file = "btf__core_reloc_" #name ".o",			\
+	.input = STRUCT_TO_CHAR_PTR(core_reloc_##name) {		\
+		.a = 1,							\
+		.b = 2,							\
+		.c = (void *)3,						\
+		.d = (void *)4,						\
+		.e = { [2] = 5 },					\
+		.f = { [1] = 6 },					\
+		.g = { .x = 7 },					\
+		.h = { .y = 8 },					\
+	},								\
+	.input_len = sizeof(struct core_reloc_##name),			\
+	.output = STRUCT_TO_CHAR_PTR(core_reloc_mods_output) {		\
+		.a = 1, .b = 2, .c = 3, .d = 4,				\
+		.e = 5, .f = 6, .g = 7, .h = 8,				\
+	},								\
+	.output_len = sizeof(struct core_reloc_mods_output),		\
+}
+
 struct core_reloc_test_case {
 	const char *case_name;
 	const char *bpf_obj_file;
···
 	PRIMITIVES_ERR_CASE(primitives___err_non_enum),
 	PRIMITIVES_ERR_CASE(primitives___err_non_int),
 	PRIMITIVES_ERR_CASE(primitives___err_non_ptr),
+
+	/* const/volatile/restrict and typedefs scenarios */
+	MODS_CASE(mods),
+	MODS_CASE(mods___mod_swap),
+	MODS_CASE(mods___typedefs),
 };
 
 struct data {

tools/testing/selftests/bpf/progs/btf__core_reloc_mods.c

···
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_mods x) {}

tools/testing/selftests/bpf/progs/btf__core_reloc_mods___mod_swap.c

···
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_mods___mod_swap x) {}

tools/testing/selftests/bpf/progs/btf__core_reloc_mods___typedefs.c

···
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_mods___typedefs x) {}

tools/testing/selftests/bpf/progs/core_reloc_types.h

···
 	int d; /* int instead of ptr */
 	int (*f)(const char *);
 };
+
+/*
+ * MODS
+ */
+struct core_reloc_mods_output {
+	int a, b, c, d, e, f, g, h;
+};
+
+typedef const int int_t;
+typedef const char *char_ptr_t;
+typedef const int arr_t[7];
+
+struct core_reloc_mods_substruct {
+	int x;
+	int y;
+};
+
+typedef struct {
+	int x;
+	int y;
+} core_reloc_mods_substruct_t;
+
+struct core_reloc_mods {
+	int a;
+	int_t b;
+	char *c;
+	char_ptr_t d;
+	int e[3];
+	arr_t f;
+	struct core_reloc_mods_substruct g;
+	core_reloc_mods_substruct_t h;
+};
+
+/* a/b, c/d, e/f, and g/h pairs are swapped */
+struct core_reloc_mods___mod_swap {
+	int b;
+	int_t a;
+	char *d;
+	char_ptr_t c;
+	int f[3];
+	arr_t e;
+	struct {
+		int y;
+		int x;
+	} h;
+	core_reloc_mods_substruct_t g;
+};
+
+typedef int int1_t;
+typedef int1_t int2_t;
+typedef int2_t int3_t;
+
+typedef int arr1_t[5];
+typedef arr1_t arr2_t;
+typedef arr2_t arr3_t;
+typedef arr3_t arr4_t;
+
+typedef const char * const volatile restrict fancy_char_ptr_t;
+
+typedef core_reloc_mods_substruct_t core_reloc_mods_substruct_tt;
+
+/* we need more typedefs */
+struct core_reloc_mods___typedefs {
+	core_reloc_mods_substruct_tt g;
+	core_reloc_mods_substruct_tt h;
+	arr4_t f;
+	arr4_t e;
+	fancy_char_ptr_t d;
+	fancy_char_ptr_t c;
+	int3_t b;
+	int3_t a;
+};

tools/testing/selftests/bpf/progs/test_core_reloc_mods.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include "bpf_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+
+static volatile struct data {
+	char in[256];
+	char out[256];
+} data;
+
+struct core_reloc_mods_output {
+	int a, b, c, d, e, f, g, h;
+};
+
+typedef const int int_t;
+typedef const char *char_ptr_t;
+typedef const int arr_t[7];
+
+struct core_reloc_mods_substruct {
+	int x;
+	int y;
+};
+
+typedef struct {
+	int x;
+	int y;
+} core_reloc_mods_substruct_t;
+
+struct core_reloc_mods {
+	int a;
+	int_t b;
+	char *c;
+	char_ptr_t d;
+	int e[3];
+	arr_t f;
+	struct core_reloc_mods_substruct g;
+	core_reloc_mods_substruct_t h;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_mods(void *ctx)
+{
+	struct core_reloc_mods *in = (void *)&data.in;
+	struct core_reloc_mods_output *out = (void *)&data.out;
+
+	if (BPF_CORE_READ(&out->a, &in->a) ||
+	    BPF_CORE_READ(&out->b, &in->b) ||
+	    BPF_CORE_READ(&out->c, &in->c) ||
+	    BPF_CORE_READ(&out->d, &in->d) ||
+	    BPF_CORE_READ(&out->e, &in->e[2]) ||
+	    BPF_CORE_READ(&out->f, &in->f[1]) ||
+	    BPF_CORE_READ(&out->g, &in->g.x) ||
+	    BPF_CORE_READ(&out->h, &in->h.y))
+		return 1;
+
+	return 0;
+}
+